<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			var a = "6"; //String
			var b = Number.parseInt(a) + 1;
			// console.log(b);

			// console.log(Number.MAX_VALUE);
			// console.log(Number.MIN_VALUE);

			//判断是否为非数字类型 NaN(不是一个数字) 是否非法
			console.log(Number.isNaN('zhagnsan' - 6)); //false
			// console.log(typeof '9'); //String

			var c = 3.1415926;
			// console.log(c.toFixed(2)); //保留小数位数(四舍五入)
		</script>
	</head>
	<body>
	</body>
</html>
